The environmental impact of our diets
by Maurice H. Alexander
When world leaders meet in Paris in November to establish a global climate agreement, they will have much to discuss. Their main targets will be carbon-fired power generation or transportation’s reliance on carbon fuels; however, there is one subject that should be near the top of their agendas. Livestock and livestock-supporting agriculture is one of the main causes of climate change due to greenhouse gases, and one that is often overlooked. Solar power and electric cars will go a long way toward stabilizing the climate, but what we choose to eat may be one of the most significant contributors to global warming—and it too may have to change.
With a rising world population and standards of living increasing in the developing world, livestock production is only set to increase. By 2050, there will be an additional 2 billion people in the world, according to the Stockholm International Water Institute. If these 2 billion more live on a meat-dependant diet, the increase in greenhouse gas emissions will be dire. Over half of the world’s pigs are in China, and as China becomes more affluent, meat production has increased even further. Between 1971 and 2010, the world population rose by 81 percent, but meat production tripled. If the trend doesn’t change, meat production will double by 2050. And meat-rich diets produce substantially more greenhouse gas emissions than vegetable-based.
A Methane Greenhouse
The principal culprit of climate change is greenhouse gases, and 18 percent of annual worldwide greenhouse gas emissions are attributable to livestock, according to a 2006 United Nations Food and Agriculture Organization (UNFAO) report. A more recent report changed their estimate of the contribution from the livestock industry to between 14.5 percent and 22 percent of the total, but estimates by other agencies have placed the proportion much higher.
In particular, cattle are a significant contributor to dangerous greenhouse gas emissions due to the large amount of methane gas they release as part of digestion, as their food ferments during rumination. Methane gas is particularly worrisome as it has a warming impact up to 25 times greater than an equivalent amount of carbon dioxide. According to the UNFAO, animal agriculture emits 44 percent of the methane produced by human activity, and cattle are by far the leading contributor.
Including the additional industries associated with livestock, such as transportation and waste byproducts, the effect is much worse. A recent report entitled Livestock and Climate Change by the World Watch Institute found that livestock and their byproducts actually account for at least 32.6 billion tons of carbon dioxide per year, or 51 percent of annual worldwide greenhouse gas emissions. This puts the global impact of entire animal industry much …
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